Joint Noise

00:01 We’re going to talk about joints right now.

00:03 We’re going to talk about joint action, joint motion, joint noise, and how they function, and what you need to know to understand the joints that you’re seeing.

00:12 So we’re going to talk about this from an osteopathic perspective and I like starting with joint cracking, popping.

00:18 We know that when we move a joint past where it would move on its own, you often hear a crack.

00:25 You may hear a pop or a pull.

00:27 You may hear nothing and just feel like you’ve got freedom of motion.

00:32 You may feel crunchiness or strumming or clicking.

00:36 Those are things we have to think about.

00:39 A crack is when the joint goes past its physiologic barrier that can move on its own towards the anatomic barrier where the joint is able to go but the muscles can’t pull it, and that’s when you get a release, you’ll hear a noise which is usually a crack but maybe a pop, and those signify a release of the joint that helps things move more freely, enhances the motion of that joint.

01:05 A “pop” is a similar type of noise that happens with movement of a joint that pulls the gas into the liquid, and when you break the surface tension, you get a pop.

01:16 You get eventration of gas into a liquid.

01:20 The gas breaks up into lots of little bubbles and then bubbles in through the liquid, the synovial fluid, and that’s called an articular pop.

01:31 A release is the crack or the pop that enhances motion and frees motion so you have greater activity and greater release and most people realize that after they do an osteopathic procedure, got it, you may have a release and you may have enhanced motion—that’s the goal.

01:50 Crepitus or crunchiness, it sounds like you’re breaking potato chips, often seen in knees or larger joints that have had some deterioration, some breakdown, some osteophyte formation, some loss of the smoothness of the joint, and it makes a crepitance sound.

02:08 It’s easily felt, often heard, and again it’s something the patients are often aware of and tell you about.

02:14 A lot of people who say they can pop their joint again and again are not popping a joint.

02:19 They’re not getting a release. They’re not enhancing motion.

02:23 They’re just strumming a ligament over a bony prominence.

02:25 Very common in the medial malleolus, lateral malleolus, where people will actively strum a joint.

02:32 They’ll just pull the ligament over the bony prominence to hear the noise.

02:36 It sounds just like a crack but it’s not a crack.

02:39 You don’t have a release.

02:42 And a tendinous click is where you can have a joint click again and again by just rubbing bones over them.

02:49 Again, no release, but a noise that sounds like a release.

02:55 This is important because in osteopathic manipulative medicine, we’re talking about joint motion, joint freedom, and what we can do to enhance activity.

03:06 A couple different types of joints— we’re going to start with the fibrous joints— bone on bone, very little motion; cartilaginous joint— a little bit more motion but still limited motion; and synovial—freely moveable joints that work in multiple axes.

03:23 One by one, starting with the fibrous joint.

03:25 Fibrous joints are synarthrosis— brining of bones together that move very little or move outside of muscle movement.

03:34 So it’s going to take fluid motion to move it.

03:37 It’s going to take respiratory force to move it but it’s not a muscle moving a bone on an axis, it’s a flowing and just gentle motion or a change in position because it’s a joint that while it becomes fixed and more fixed as time goes on, it’s not fully fixed.

03:58 So it’s united by fibrous connective tissue like the sutures of the skull and like a gomphoses, the joint of the tooth in the tooth socket— these are fibrous joints.

04:10 Cartilaginous joints have small amounts of motion.

04:15 They do not have a joint capsule.

04:17 They don’t flow smoothly, but they do move and they are held together and kept in a specific system of motion and activity.

04:29 So generally, it’s got a fibrocartilaginous disc that keeps some squishy stuff, some fluid, the nucleus pulposus and annulus fibrosus inside that allows for motion and there multiple cartilaginous joints that help our body move but not quickly, mostly slow and small amounts.

04:51 Synovial joints have the most motion.

04:53 They’re freely moveable.

04:54 Their motion is dictated by the shape of the joint and we talk about the movements by the direction that the bones move.

05:03 So let’s talk about synovial joints which are mostly fluid and gas— have a bit of a pressure in there.

05:10 So the motion of the joint is important to describe.

05:14 If we’re talking about flexion and extension that’s motion in the sagittal plane, like the sagittal ridge, and flexion is when you move it up and extension is when you move it back.

05:25 Again, in the sagittal plane, flexion and extension.

05:30 If you look at the frontal plane, like you cut the body this way, you have abduction away from the body and adduction towards the body or adding to the body.

05:42 If you go for a transverse plane, you’ll have internal rotation and external rotation of the joints.

05:50 So naming the motion is helpful and helps with conversations.

05:57 When you talk about synovial joints, many of them have one axis of motion.

06:02 So if we’re talking about flexion and extension, that’s one action.

06:07 You can have a biaxial joint like the wrist that’ll have multiple ways of moving— flex and extend, abduct and adduct, and you can even have some rotation of it.

06:20 So if you have two degrees of freedom, if you have flexion and extension, and abduction and adduction, that’s a biaxial joint.

06:30 A multiaxial joint like the shoulder will have three degrees of motion so you’ll have your flexion, abduction, and you can move internally and externally.

06:40 You can have a hinge joint, again, like the elbow that’s one degree of freedom, one type of motion.

06:46 You can have circumduction where you can move it in circles which is two degrees or three degrees and you can have movement with perpendicular axes as well.

06:57 When you talk about joint motion, it’s important to know whether it’s active— the person’s doing it themselves or passive—being helped by a provider.

07:06 Muscles can move the same joint in different ways depending on how the contraction goes and you can even use contraction and less contraction as giving you different motions or a reverse type of motion.

07:18 So if you’re doing a sit up, you can flex to get up and then flex less to allow yourself down.

07:28 Muscle contraction can be concentric, eccentric, or isometric.

07:33 Concentric is normal muscle contraction where the muscle fibers shorten in order to accomplish activity, pulling the muscle together.

07:41 Eccentric is where the muscle lengthens during the contraction, so the contractions are anti-gravity.

07:49 And isometric is muscle pushing against each other without much motion but with contraction of the muscle.

07:57 So in talking about joints, it’s important to differentiate from the anatomic barrier and the physiologic barrier, and I’m also going to throw a third thing in there called the pathologic barrier.

08:07 So the physiologic barrier is how much your muscle can do on its own.

08:11 The anatomic barrier is given help, given the ability to do more— what would the joint be able to do if somebody helped move it or moved it to its endpoint.

08:21 That is the anatomic barrier.

08:25 And the pathologic barrier is if you have somatic dysfunction or some other kind of problem where you can’t go past an activity because of the disease, and that’s the pathologic barrier.

08:37 So we generally function within the physiologic barrier but the anatomic barrier is something that a provider needs to know so you don’t cause damage and identifying a pathologic barrier or disease causing limitation will give you goals in the treatment of a person.